#!/bin/rc
# patch/diff [-w] patch-name
rfork e
fn usage {
	echo 'usage: patch/diff [-bmnwz] patch-name' >[1=2]
	exit usage
}

dopts=(-c)
while (! ~ $#* 0 && ~ $1 -*) {
	switch ($1) {
	case -[bmnw]
		dopts=($dopts $1)
	case -z
		dopts=()
	case *
		usage
	}
	shift
}
if(! ~ $#* 1)
	usage

if(! test -d /n/sources/patch){
	rfork n
	9fs sources
}

if(! test -d /n/sources/patch/$1){
	echo 'no such patch' /n/sources/patch/$1 >[1=2]
	exit nopatch
}

builtin cd /n/sources/patch/$1 || exit nopatch
if(! patch/okay .){
	echo 'bad patch: '$status >[1=2]
	exit badpatch
}

d=/n/sources/patch/$1
fn xxx {
	echo $1
	diff $dopts $2.orig $d/$2 | sed 's/^/	/'
}
cat files | sed 's/^/xxx /' | rc